CN101806954B

CN101806954B - Zoom lens and image pickup apparatus

Info

Publication number: CN101806954B
Application number: CN2010101146182A
Authority: CN
Inventors: 畠山丈司
Original assignee: Sony Corp
Current assignee: Sony Corp
Priority date: 2009-02-18
Filing date: 2010-02-20
Publication date: 2012-12-05
Anticipated expiration: 2030-02-20
Also published as: JP4737570B2; CN101806954A; US20100214665A1; JP2010191214A

Abstract

A zoom lens and an image pickup apparatus having such a zoom lens are provided. The zoom lens includes a first lens group in which each lens has negative refractive power, a second lens group in which each lens has positive refractive power, a third lens group in which each lens has positive refractive power. These lens groups are arranged in this order from an object side to an image side. The first lens group includes a negative lens and a positive lens which are arranged in this order from an image side to an object side. The third lens group includes a positive lens. Both surfaces of the negative lens of the first lens group are aspherical surfaces, respectively. Both surfaces of the positive surfaces of the third lens group are aspherical surfaces, respectively.

Description

Zoom lens and image pick-up device

Technical field

The present invention relates to zoom lens and image pick-up device.Particularly; The present invention relates to zoom lens that will in digital camera, digital camera etc., use and technical field with image pick-up device of this zoom lens; Aspect the thickness of these zoom lens on depth direction reduces is excellent; Have wide-angle simultaneously and in the high zoom ratios of the focal length of wide-angle side, and in the correction of visual field crooked (field curvature), be superior.

Background technology

In recent years, use the image pick-up device (like digital camera and digital camera) of the solid-state imaging apparatus with a large amount of pixels increased popularity that become, this requires more that high image quality and thickness reduce.Particularly, under these circumstances, the zoom lens that required in image pick-up device, to install have more long-focus in wide-angle side; High zoom ratios; From wide-angle side to dolly-out, dolly-back the end and from infinite as far as closely the imaging gamut on excellent imaging performance; And the thickness that on depth of field direction, reduces.

In recent years, for the thickness of realizing image pick-up device reduces, mainly adopted so-called telescopic lens system.Optical system is wherein given prominence to and when not taking, be contained in the telescopic lens system from device main body when taking.Yet because the lens configuration when holding, the telescopic lens system possibly cause the increase of thickness.

For example; As the zoom lens that are suitable for small digital camera; Many zoom lens have been proposed, make its each by on the direction from the subject side to the image-side by three lens combination structures of following sequence arrangement: have first lens combination of negative refractive power, the 3rd lens combination that has second lens combination of positive refractive power and have positive refractive power.

Increased zooming range applicable to some zoom lens image pick-up device with a large amount of pixels, that have this three set constructors; And can guarantee from wide-angle to dolly-out,ing dolly-back end and from infinite gamut (for example, referring to the open No.11-194274 of Japanese Unexamined Patent Application, 2002-90624 and 11-287953) as far as closely imaging.

In addition, have another kind of zoom lens, its can through the electronic image of the view data of catching by solid-state imaging apparatus handle and further miniaturization (for example, referring to the open No. of Japanese Unexamined Patent Application

Summary of the invention

Yet for the zooming range that obtains to increase, the zoom lens of in the open No.11-194274 of Japanese Unexamined Patent Application, describing are through providing four entirety of lens package in second lens combination second lens combination of four lens arrangement.Yet in the case, for second lens, four lens quantitatively are high, make that the thickness of second lens combination is big dimensionally, and its size that will be difficult to be implemented in when holding reduce.

In addition, the zoom lens of in the open No.2002-90624 of Japanese Unexamined Patent Application, describing are tending towards the zooming range that provides extra lens combination (the 4th lens combination) to obtain to increase through for the typical zoom lens with three lens combination.This extra lens group is an effective fixation group in the correction of off-axis aberration.Yet, because the increase of lens numbers is difficult to when holding realize that thickness reduces.

In addition, the zoom lens of in the open No.11-287953 of Japanese Unexamined Patent Application, describing focus on through during closely forming images, carrying out in mobile first lens combination on the optical axis direction.Yet first lens combination has big lens diameter, makes the driving mechanism of lens combination also can enlarge.Therefore, be difficult to realize enough miniaturizations of zoom lens.In addition, first lens combination is by three lens arrangement.Particularly, its thickness that has hindered when holding reduces.

In addition, handle the negative refractive power that increases first lens with the electronic image of carries out image data, make that the zoom lens of in the open No.2006-284790 of Japanese Unexamined Patent Application, describing are littler through the design zoom lens.Yet in the case, because the variation of the increase of the off-axis aberration (like astigmatism and visual field bending) that when the variation of distance of the object of the end of dolly-out,ing dolly-back, occurs, it causes the reduction of optical property.

Because above-mentioned situation; Expectation is shortened at the focal length of the wide-angle side zooming range to realize extensive angle more and to obtain to increase; Make holding to dolly-out,ing dolly-back from wide-angle and as far as the gamut of closely imaging, can guaranteeing good imaging performance, to reduce the thickness of zoom lens from infinite.

According to the embodiment of the invention, a kind of zoom lens comprise: first lens combination with negative refractive power; Second lens combination with positive refractive power; And the 3rd lens combination with positive refractive power; Said three lens combination are arranged from the subject side to the image-side in order; And configuration as follows: in said zoom lens; When the lens position state changes to when dolly-out,ing dolly-back the end state from the wide-angle side state; Said second lens combination moves towards object on optical axis direction, and said first lens combination and said the 3rd lens combination move on the said optical axis direction with reduce the interval between said first lens combination and said second lens combination and increase said second lens combination and said the 3rd lens combination between the interval.In addition, in said zoom lens, when changing object's position, focus on through the mobile execution short distance of said the 3rd lens combination on optical axis direction.In addition, in said zoom lens, said first lens combination comprises the negative lens and the positive lens of the sequence arrangement from the image-side to the subject side.Said the 3rd lens combination comprises positive lens.Two surfaces of the said negative lens of said first lens combination are respectively aspheric surfaces.In addition, two of the said positive lens of said the 3rd lens combination surfaces are respectively aspheric surfaces.

Therefore, comprise two lens and lens in the 3rd lens combination in first group according to the zoom lens of the embodiment of the invention.

Preferably, in above-mentioned zoom lens, said second lens combination can comprise two positive lenss and a negative lens.

Through constructing second lens combination from two positive lenss and a negative lens, lens correction spherical aberration that can be through lesser amt, astigmatism, aberration etc.

Preferably, above-mentioned zoom lens can have at least one aspheric surface in second lens combination.

Through being that second lens combination provides at least one aspheric surface, sphere can represent the function of aberration correction, like spherical aberration, astigmatism and aberration.

Preferably, in above-mentioned zoom lens, second lens combination can be designed on the direction vertical with optical axis, squint with migrated image basically.

When second lens combination is designed on the direction vertical with optical axis, squint with migrated image basically, can use lightweight second lens combination to come the carries out image skew with relatively little lens diameter.

According to another embodiment of the present invention; A kind of image pick-up device; Comprise zoom lens and will convert the imaging device of electric signal into by the optical imagery that said zoom lens form; And this zoom lens configuration as follows: said zoom lens comprise first lens combination with negative refractive power, the 3rd lens combination that has second lens combination of positive refractive power and have positive refractive power, and said three lens combination are arranged from the subject side to the image-side in order.In these zoom lens; When the positioning lens state changes to when dolly-out,ing dolly-back the end state from the wide-angle side state; Said second lens combination moves towards object on optical axis direction, and said first lens combination and said the 3rd lens combination move on the said optical axis direction with reduce the interval between said first lens combination and said second lens combination and increase said second lens combination and said the 3rd lens combination between the interval.In addition, in these zoom lens, when changing object's position, focus on through the mobile execution short distance of said the 3rd lens combination on optical axis direction.Said first lens combination comprises from the image-side to the subject side negative lens and the positive lens with following sequence arrangement.In addition, in these zoom lens, said the 3rd lens combination comprises positive lens.Two surfaces of the said negative lens of said first lens combination are respectively aspheric surfaces.Two surfaces of the said positive lens of said the 3rd lens combination are respectively aspheric surfaces.

Therefore, comprise first group two lens and lens of the 3rd lens combination according to the zoom lens in the image pick-up device of the embodiment of the invention.

As stated, the zoom lens of any embodiment comprise according to the present invention: have first lens combination of negative refractive power, the 3rd lens combination that has second lens combination of positive refractive power and have positive refractive power.These lens combination are pressed this sequence arrangement from the subject side to the image-side.When the positioning lens state changes to when dolly-out,ing dolly-back the end state from the wide-angle side state; Said second lens combination moves towards object on optical axis direction, and said first lens combination and said the 3rd lens combination move on the said optical axis direction with reduce the interval between said first lens combination and said second lens combination and increase said second lens combination and said the 3rd lens combination between the interval.Then, when changing object's position, focus on through the mobile execution short distance of said the 3rd lens combination on optical axis direction.In zoom lens, as stated, said first lens combination comprises from the image-side to the subject side negative lens and the positive lens with following sequence arrangement.In addition, said the 3rd lens combination comprises positive lens.Two surfaces of the said negative lens of said first lens combination are respectively aspheric surfaces.Two surfaces of the said positive lens of said the 3rd lens combination are respectively aspheric surfaces.Therefore, zoom lens satisfy following conditions expression formula (1) to (4):

(1)0.10＜ASPa1＜0.36；

(2)-0.05＜ASPa2＜-0.02；

(3) 0＜ASPb1＜0.20; And

(4) 0.04＜ASPb2＜0.15, wherein

ASPa1＝(ZAa1-ZRa1)/{Ca1·(Na-1)·f1}，

ASPa2＝(ZAa2-ZRa2)/{Ca2·(1-Na)·f1}，

ASPb1＝(ZAb1-ZRb1)/{Cb1·(Nb-1)·f3}，

ASPb2＝(ZAb2-ZRb2)/{Cb2·(1-Nb)·f3}，

Da: the thickness of the said negative lens on the said optical axis of said first lens combination,

Db: the thickness of the said positive lens on the said optical axis of said first lens combination,

Ya＝4Da，

Yb＝2Db，

ZRa1: the optical axis of the paraxial curvature surface of subject side of the said negative lens from said first lens combination, be in the coordinate on the optical axis direction at height corresponding to Ya,

ZRa2: the optical axis of the paraxial curvature surface of image-side of the said negative lens from said first lens combination, be in the coordinate on the optical axis direction at height corresponding to Ya;

ZAa1: the aspheric optical axis of subject side of the said negative lens from said first lens combination, be in the coordinate on the optical axis direction at height corresponding to Ya;

ZAa2: the aspheric optical axis of image-side of the said negative lens from said first lens combination, be in the coordinate on the optical axis direction at height corresponding to Ya;

Ca1: the aspheric paraxial curvature of the subject side of the said negative lens in said first lens combination,

Ca2: the aspheric paraxial curvature of the image-side of the said negative lens in said first lens combination,

Na: the refractive index of the e line of the said negative lens in said first lens combination,

F1: the focal length of said first lens combination,

ZRb1: the optical axis of the paraxial curvature surface of subject side of the said positive lens from said first lens combination, be in the coordinate on the optical axis direction at height corresponding to Yb,

ZRb2: the optical axis of the paraxial curvature surface of image-side of the said positive lens from said first lens combination, be in the coordinate on the optical axis direction at height corresponding to Yb;

ZAb1: the aspheric optical axis of subject side of the said positive lens from said first lens combination, be in the coordinate on the optical axis direction at height corresponding to Yb;

ZAb2: the aspheric optical axis of image-side of the said positive lens from said first lens combination, be in the coordinate on the optical axis direction at height corresponding to Yb;

Cb1: the aspheric paraxial curvature of the subject side of the said positive lens in said first lens combination,

Cb2: the aspheric paraxial curvature of the image-side of the said positive lens in said first lens combination,

Nb: the refractive index of the e line of the said positive lens in said first lens combination, and

F3: the focal length of said the 3rd lens combination.

Therefore, the focal length that can shorten wide-angle side to be obtaining more extensive angle, and can realize the zooming range that increases.In addition, holding to dolly-out,ing dolly-back from wide-angle and as far as the gamut of closely imaging, can guarantee good imaging performance from infinite.Therefore, can realize that thickness reduces.

In the zoom lens according to second embodiment of the invention, second lens combination comprises two positive lenss and a negative lens.

Therefore, can use the lens correction spherical aberration, astigmatism, aberration etc. of lesser amt.In addition, the thickness that can realize zoom lens reduces.

In each the zoom lens of third and fourth embodiment according to the present invention, at least one surface of the lens in second lens combination has aspheric surface.

Therefore, can use the further correcting spherical aberration of lens, astigmatism, aberration etc. of lesser amt.In addition, can realize high image quality.

In each the zoom lens of the 5th and the 8th embodiment according to the present invention, second lens combination can be basically on the direction vertical with optical axis skew with migrated image.

Therefore, because second lens combination is in light weight and its lens diameter is little, can minimize the driving mechanism that is used for vibration control.

The image pick-up device of the embodiment of the invention comprises zoom lens and will convert the imaging device of electric signal through the optical imagery that zoom lens form into.Zoom lens comprise: have first lens combination of negative refractive power, the 3rd lens combination that has second lens combination of positive refractive power and have positive refractive power, these lens combination are pressed this sequence arrangement from the subject side to the image-side.

When the positioning lens state changes to when dolly-out,ing dolly-back the end state from the wide-angle side state; Said second lens combination moves towards object on optical axis direction, and said first lens combination and said the 3rd lens combination move on the said optical axis direction with reduce the interval between said first lens combination and said second lens combination and increase said second lens combination and said the 3rd lens combination between the interval.Then, when changing object's position, focus on through the mobile execution short distance of said the 3rd lens combination on optical axis direction, said first lens combination comprises from the image-side to the subject side negative lens and the positive lens with following sequence arrangement.Said the 3rd lens combination comprises positive lens.Two surfaces of the said negative lens of said first lens combination are respectively aspheric surfaces.Two surfaces of the said positive lens of said the 3rd lens combination are respectively aspheric surfaces.In addition, zoom lens satisfy following conditions expression formula (1) to (4):

(1)0.10＜ASPa1＜0.36；

(2)-0.05＜ASPa2＜-0.02；

(3) 0＜ASPb1＜0.20; And

(4) 0.04＜ASPb2＜0.15, wherein

ASPa1＝(ZAa1-ZRa1)/{Ca1·(Na-1)·f1}，

ASPa2＝(ZAa2-ZRa2)/{Ca2·(1-Na)·f1}，

ASPb1＝(ZAb1-ZRb1)/{Cb1·(Nb-1)·f3}，

ASPb2＝(ZAb2-ZRb2)/{Cb2·(1-Nb)·f3}，

Ya＝4Da，

Yb＝2Db，

F1: the focal length of said first lens combination,

F3: the focal length of said the 3rd lens combination.

Therefore, can shorten at the focal length of wide-angle side obtaining more extensive angle, and can realize the zooming range that increases.In addition, holding to dolly-out,ing dolly-back from wide-angle and as far as the gamut of closely imaging, can guarantee good imaging performance from infinite.Therefore, can realize that thickness reduces.

Particularly, using wherein optical system can from device main body, give prominence to and be contained under the situation of the telescopic lens type image pick-up device in the device main body, the thickness that can be implemented in when holding optical system reduces.

Description of drawings

Fig. 1 is the figure that diagram is arranged according to the lens of the zoom lens of first embodiment of the invention, and its expression is used for to be similar to Fig. 2 realizes image pick-up device and zoom lens to the mode of Figure 26 optimal mode;

Fig. 2 is the figure of spherical aberration, astigmatism and distorton aberration during being shown in infinite distance under the wide-angle side state and focusing on, its expression be similar to Fig. 3 to the mode of Fig. 5 with the aberration curve figure of concrete numerical applications to the numerical example of first embodiment;

Fig. 3 is the figure of spherical aberration, astigmatism and distorton aberration during the infinite distance focusing that is shown under the intermediate focus location status;

Fig. 4 is the figure of spherical aberration, astigmatism and distorton aberration during the infinite distance focusing that is shown under the end state of dolly-out,ing dolly-back;

Fig. 5 is the figure that is shown in spherical aberration, astigmatism and distorton aberration during the focusing of the object distance with 2m under the angle end state of dolly-out,ing dolly-back;

Fig. 6 is the figure that diagram is arranged according to the lens in the zoom lens of second embodiment of the invention;

Fig. 7 is the figure of spherical aberration, astigmatism and distorton aberration during being shown in infinite distance under the wide-angle side state and focusing on, its expression wherein be similar to Fig. 8 to the mode of Figure 10 with the aberration curve figure of concrete numerical applications to the numerical example of first embodiment;

Fig. 8 is the figure of spherical aberration, astigmatism and distorton aberration during the infinite distance focusing that is shown under the intermediate focus location status;

Fig. 9 is the figure of spherical aberration, astigmatism and distorton aberration during the infinite distance focusing that is shown under the end state of dolly-out,ing dolly-back;

Figure 10 is the figure that is shown in spherical aberration, astigmatism and distorton aberration during the focusing of the object distance that has 2m under the angle end state of dolly-out,ing dolly-back;

Figure 11 is the figure that diagram is arranged according to the lens of the zoom lens of third embodiment of the invention;

Figure 12 is the figure of spherical aberration, astigmatism and distorton aberration during being shown in infinite distance under the wide-angle side state and focusing on, and its expression is to be similar to Figure 13 to the mode of Figure 15 aberration curve figure with the numerical example of concrete numerical applications to the three embodiment;

Figure 13 is the figure of spherical aberration, astigmatism and distorton aberration during the infinite distance focusing that is shown under the intermediate focus location status;

Figure 14 is the figure of spherical aberration, astigmatism and distorton aberration during the infinite distance focusing that is shown under the end state of dolly-out,ing dolly-back;

Figure 15 is the figure that is shown in spherical aberration, astigmatism and distorton aberration during the focusing of the object distance with 2m under the angle end state of dolly-out,ing dolly-back;

Figure 16 is the figure that diagram is arranged according to the lens of the zoom lens of fourth embodiment of the invention;

Figure 17 is the figure of spherical aberration, astigmatism and distorton aberration during being shown in infinite distance under the wide-angle side state and focusing on, and its expression is to be similar to Figure 18 to the mode of Figure 20 aberration curve figure with the numerical example of concrete numerical applications to the four embodiment;

Figure 18 is the figure of spherical aberration, astigmatism and distorton aberration during the infinite distance focusing that is shown under the intermediate focus location status;

Figure 19 is the figure of spherical aberration, astigmatism and distorton aberration during the infinite distance focusing that is shown under the end state of dolly-out,ing dolly-back;

Figure 20 is the figure that is shown in spherical aberration, astigmatism and distorton aberration during the focusing of the object distance with 2m under the angle end state of dolly-out,ing dolly-back;

Figure 21 is the figure that diagram is arranged according to the lens of the zoom lens of fifth embodiment of the invention;

Figure 22 is the figure of spherical aberration, astigmatism and distorton aberration during being shown in infinite distance under the wide-angle side state and focusing on, and its expression is to be similar to Figure 23 to the mode of Figure 25 aberration curve figure with the numerical example of concrete numerical applications to the five embodiment;

Figure 23 is the figure of spherical aberration, astigmatism and distorton aberration during the infinite distance focusing that is shown under the intermediate focus location status;

Figure 24 is the figure of spherical aberration, astigmatism and distorton aberration during the infinite distance focusing that is shown under the end state of dolly-out,ing dolly-back;

Figure 25 is the figure that is shown in spherical aberration, astigmatism and distorton aberration during the focusing of the object distance with 2m under the angle end state of dolly-out,ing dolly-back;

Figure 26 illustrates the block diagram of image pick-up device according to an embodiment of the invention.

Embodiment

Below, with the zoom lens and the image pick-up device that illustrate and describe according to the embodiment of the invention.

[configurations of zoom lens]

At first, zoom lens according to an embodiment of the invention will be described.

Zoom lens according to the embodiment of the invention comprise first lens combination with negative refractive power with the sequence arrangement from the subject side to the image-side, the 3rd lens combination that has second lens combination of positive refractive power and have positive refractive power.

In the zoom lens of present embodiment; When the positioning lens state changes to when dolly-out,ing dolly-back the end state from the wide-angle side state; Second lens combination moves towards object on optical axis direction, and first lens combination and the 3rd lens combination move on the optical axis direction with reduce the interval between first lens combination and second lens combination and increase by second lens combination and the 3rd lens combination between the interval.

In addition, in the zoom lens of present embodiment, when changing object's position, focus on through the mobile execution short distance of the 3rd lens combination on optical axis direction.

In addition, in the zoom lens of present embodiment, first lens combination comprises from the image-side to the subject side negative lens and the positive lens with this sequence arrangement.The 3rd lens combination comprises positive lens.Two surfaces of the negative lens of first lens combination are respectively aspheric surfaces.Two surfaces of the positive lens of the 3rd lens combination are respectively aspheric surfaces.

In the zoom lens of present embodiment, as stated, first lens combination comprises negative lens and positive lens, and wherein two of each lens surfaces are aspheric surfaces.The 3rd lens combination comprises its two positive lenss that the surface is an aspheric surface.

Therefore, the quantity of the lens in each lens combination is made as enough advantageously lens of the minimum number of correcting spherical aberration, astigmatism, aberration etc.Can realize that thickness reduces, particularly, can be implemented in use optical system wherein can be from device main body outstanding and hold under the situation of telescopic lens type image pick-up device wherein, the thickness when holding optical system reduces.

The zoom lens of present embodiment are configured to satisfy following conditions expression formula (1) and arrive (4):

(1)0.10＜ASPa1＜0.36；

(2)-0.05＜ASPa2＜-0.02；

(3) 0＜ASPb1＜0.20; And

(4) 0.04＜ASPb2＜0.15, wherein

ASPa1＝(ZAa1-ZRa1)/{Ca1·(Na-1)·f1}，

ASPa2＝(ZAa2-ZRa2)/{Ca2·(1-Na)·f1}，

ASPb1＝(ZAb1-ZRb1)/{Cb1·(Nb-1)·f3}，

ASPb2＝(ZAb2-ZRb2)/{Cb2·(1-Nb)·f3}，

Ya＝4Da，

Yb＝2Db，

ZRa2: the optical axis of the image-side of the said negative lens from said first lens combination, be in the coordinate on the optical axis direction at height corresponding to Ya;

F1: the focal length of said first lens combination,

ZRb2: the optical axis of the image-side of the said positive lens from said first lens combination, be in the coordinate on the optical axis direction at height corresponding to Yb;

F3: the focal length of said the 3rd lens combination.In addition, above-mentioned e line has the wavelength of 546.07nm.

If the lower limit of value less-than condition expression formula (1) then is difficult to obtain aspheric effect.Therefore, in the case, because the plane of delineation causes the under-exposure of wide-angle side, the sphere simple lens becomes and is difficult to aberration correction.Particularly; If the negative refractive power on the subject side of the negative lens in first lens combination surface strengthens gradually; Then about the use of the positive lens in the 3rd lens of the off-axis aberration that is used for proofreading and correct the negative lens in first lens combination, becoming is difficult in wide-angle side and dolly-out,s dolly-back and find balance between the end.As a result, when when the end of dolly-out,ing dolly-back is taken the photograph the body variable in distance, the visual field bending greatly changes.

On the other hand, if value surpasses the upper limit of conditional expression (1), then the effect of non-spherical surface became strong.Because cause the result of the overexposure of wide-angle side, becoming is difficult to advantageously aberration correction.

Therefore, the expression formula (1) as long as zoom lens satisfy condition just can reasonably represent aspheric effect.Therefore, the aberration compensation that can carry out is to improve the optical property of zoom lens.

If value is lower than the lower limit of conditional expression (2), then aspheric effect became strong.Therefore, in the case, because the plane of delineation causes the under-exposure of wide-angle side, the sphere simple lens becomes and is difficult to aberration correction.

On the other hand, if value surpasses the upper limit of conditional expression (2), then be difficult to obtain aspheric effect.Because cause the result of the overexposure of wide-angle side, becoming is difficult to advantageously aberration correction.Particularly, if the negative refractive power on the image-side of the negative lens in first lens combination surface strengthens gradually, then the curvature of the marginal portion of lens becomes big.Therefore, the difficulty of the formation of the negative lens in first lens combination will increase.

Therefore, the expression formula if zoom lens satisfy condition (2) then can reasonably represent aspheric effect.Therefore, in the case, carry out good aberration compensation.As a result, can obtain the improvement of optical property and the simplification of the negative lens in first lens combination forms.

If value is lower than the lower limit of conditional expression (3), then be difficult to obtain aspheric effect.The result of the overexposure of holding owing to cause dolly-out,ing dolly-back, becoming is difficult to advantageously aberration correction.

If value surpasses the upper limit of conditional expression (3), then aspheric effect became strong, therefore, and the plane of delineation be tending towards causing the dolly-out,ing dolly-back under-exposure of end.In addition, owing to became strong through the crooked calibration result in aspheric visual field, therefore when when the end of dolly-out,ing dolly-back is taken the photograph the body variable in distance, the crooked marked change in visual field.

Therefore, the expression formula if zoom lens satisfy condition (3) then can reasonably represent aspheric effect.The aberration compensation that can carry out is to improve the optical property of zoom lens.

If value is lower than the lower limit of conditional expression (4), then be difficult to obtain aspheric effect.Therefore, in the case, the under-exposure of end because the plane of delineation causes dolly-out,ing dolly-back, the sphere simple lens becomes and is difficult to aberration correction.

If value surpasses the upper limit of conditional expression (4), then aspheric effect became strong, therefore, and the plane of delineation be tending towards causing the dolly-out,ing dolly-back overexposure of end.In addition, owing to became strong through the crooked calibration result in aspheric visual field, therefore when when the end of dolly-out,ing dolly-back is taken the photograph the body variable in distance, the crooked marked change in visual field.

Therefore, the expression formula (4) as long as zoom lens satisfy condition just can reasonably represent aspheric effect.The aberration compensation that can carry out is to improve the optical property of zoom lens.

In the zoom lens according to the embodiment of the invention, preferably, second lens combination comprises two positive lenss and a negative lens.

Because second lens combination is made up of two positive lenss and a negative lens, therefore can uses the lens correction spherical aberration, astigmatism, aberration of lesser amt etc., and can realize that the thickness of zoom lens reduces.

In the zoom lens of first embodiment of the invention, preferably, at least one surface of the lens in second lens combination has aspheric surface.

Because at least one surface of the lens in second lens combination has aspheric surface, so can use the further correcting spherical aberration of the lens of lesser amt, astigmatism, chromatic dispersion etc.In addition, can realize high image quality.

In the zoom lens according to the embodiment of the invention, second lens combination can be designed on perpendicular to the direction of optical axis, squint with migrated image basically.

Second lens combination can be basically perpendicular on the direction of optical axis skew with migrated image.Therefore, because second lens combination is in light weight and its lens diameter is little, therefore can minimize the driving mechanism that is used for vibration control.

Alternative change is used for the diameter of aperture of the adjusting of light quantity, and for size reduces and prevents the aperture diffraction by deterioration, the use of neutral (ND) optical filter or liquid crystal light modulation equipment is preferred.

In addition, for reducing the diameter of the lens in first lens combination, carry out the electronic image processing and reduce with the further size that realizes zoom lens.

[embodiment]

Referring now to accompanying drawing and table, with the zoom lens of describing each specific embodiment and its numerical example of having used concrete numerical value according to the present invention.

Below the implication of the symbol of expression is following in description and the table:

" si " expression is from " i " individual surface of subject side; The radius-of-curvature on " ri " expression " i " individual surface; Distance between the surface of the first surface on " di " expression " i " individual surface and the axle; " ni " is illustrated in the refractive index that d line (wavelength is 587.6nm) has the material of " i " surperficial lens; And " vi " is illustrated in the Abbe number (Abbe number) that the d line has the material of " i " surperficial lens.

About " si ", the corresponding surface of " ASP " expression is an aspheric surface.About " ri ", the corresponding surface of " INFINITY " expression is the plane.About " di ", what " variable " expression related to is variable interval at interval.

In addition, " Fno " expression F number, and " ω " expression half angle of view.

The lens that use in each numerical example have aspherical lens surface.

Be positioned on the summit on surface under the situation of initial point, optical axis direction is the X axle, and is " h " perpendicular to the height of the lens of optical axis.Therefore, aspheric profile can be represented through equation:

[equality 1]

X = \frac{h^{2} / R}{1 + \sqrt{1 - (1 + K) h^{2} / R^{2}}} + Σ A_{i} h^{i}

Wherein, " Ai " expression " i " individual aspheric coefficient; The radius-of-curvature of " R " expression lens; And the conic constants of " K " expression lens.

As the lens combination that comprises according to each of the

zoom lens

1,2 of the example of first, second and the lens of the 3rd embodiment and 3 from the subject side to the image-side with following sequence arrangement: wherein each lens has the first lens combination GR1 of negative refractive power; Wherein each lens has the second lens combination GR2 of positive refractive power; And wherein each lens has the 3rd lens combination GR3 of positive refractive power.

In addition; In

zoom lens

1,2 and 3; When the positioning lens state changes to when dolly-out,ing dolly-back the end state from the wide-angle side state; The second lens combination GR2 moves towards object on optical axis direction, and the first lens combination GR1 and the 3rd lens combination GR3 move on optical axis direction, with reduce the interval between the first lens combination GR1 and the second lens combination GR2 and increase the second lens combination GR2 and the 3rd lens combination GR3 between the interval.

In addition, in each of

zoom lens

1,2 and 3, when changing object's position, carry out short distance through the 3rd lens combination GR3 moving on optical axis direction and focus on.

< first embodiment >

Fig. 1 is the figure that diagram is arranged according to the lens of the zoom lens 1 of first embodiment of the invention.Zoom lens 1 comprise six lens.

The first lens combination GR1 comprises that with the negative lens G1 of the sequence arrangement from the subject side to the image-side and positive lens G2 in negative lens G1, two surfaces form aspheric surface.

The second lens combination GR2 comprises that wherein two surfaces form aspheric positive lens G3, positive lens G4 and negative lens G5.These lens G3, G4 and G5 combine bonding to form (cemented) lens, simultaneously with the sequence arrangement from the subject side to the image-side.The second lens combination GR2 can move on almost vertical with optical axis direction.Therefore, the mobile permission image shift of the second lens combination GR2 on almost vertical direction with optical axis.

The 3rd lens combination GR3 comprises that wherein two surfaces form aspheric positive lens.In the subject side of the second lens combination GR2, aperture diaphragm IR (aperture surface s5) is arranged near the second lens combination GR2.During zoom, aperture diaphragm IR moves on optical axis direction, makes up with the second lens combination GR2 simultaneously.

Low-pass filter LPF is arranged between the 3rd lens combination GR3 and the plane of delineation IMG.

Table 1 is represented the lens data through the numerical example 1 of zoom lens 1 acquisition that numerical value specifically is applied to first embodiment.

[table 1]

si	ri	di	ni	vi
					1(ASP)	95.9106	0.800	1.85135	40.1
2(ASP)	5.9455	1.750
					3	9.5790	1.400	1.92286	20.9
4	19.2682	Variable
					5 (aperture diaphragms)	INFINITY	-0.350

6(ASP)	5.5086	1.600	1.69350	53.2
					7(ASP)	-24.1779	0.100
8	8.4638	1.500	1.83481	42.7
					9	-15.1629	0.430	1.74077	27.8
10	3.3558	Variable
					11(ASP)	25.2096	1.550	1.52470	56.2
12(ASP)	-13.4092	Variable
					13	INFINITY	0.300	1.51680	64.2
14	INFINITY

In zoom lens 1, the image-side of the positive lens G6 of the subject side of the positive lens G6 of the image-side of the positive lens G3 of the subject side of the positive lens G3 of the image-side of the negative lens G1 of the subject side of the negative lens G1 of first lens combination GR1 surface (s1), first lens combination GR1 surface (s2), second lens combination GR2 surface (s6), second lens combination GR2 surface (s7), the 3rd lens combination GR1 surface (s11) and the 3rd lens combination GR3 surface (s12) forms aspheric surface respectively.

In addition, aspheric taper COEFFICIENT K and aspheric the 4th, the 6th, the 8th and the tenth asphericity coefficient A4, A6, A8 and the A10 in the table 2 expression numerical example 1.

In addition, in table 2 and each of other tables like the said expression asphericity coefficient in back, " E-i " expression has the exponential function at the end 10.In other words, its expression " 10-i ", for example, " 0.12345E-05 " expression " 0.12345 * 10-5 ".

[table 2]

si

K

A4

A6

A8

A10

1

0

-6.42289E-04

3.39503E-05

-7.19731E-07

5.95570E-09

2

0

-1.04324E-03

2.87452E-05

-1.44284E-07

-1.79880E-08

6

0

-8.49760E-04

1.95967E-05

-9.93054E-06

7.25102E-07

7

0

1.65345E-04

5.00454E-05

-1.67177E-05

1.48923E-06

11

0

8.80734E-04

-1.36593E-04

9.01929E-06

-1.97908E-07

12

0

1.72259E-03

-2.13523E-04

1.28850E-05

-2.70775E-07

In zoom lens 1; During wide-angle side state and the zoom between the end state of dolly-out,ing dolly-back, surface distance d10 between the surface distance d4 between the first lens combination GR1 and the aperture diaphragm IR, the second lens combination GR2 and the 3rd lens combination GR3 and the surface distance d12 between the 3rd lens combination GR3 and the low-pass filter LPF change.The F that table 3 is illustrated under wide-angle side state (focal length=5.15), intermediate focus location status (focal length=10.01) and the end state of dolly-out,ing dolly-back (focal length=19.49) in the numerical example 1 counts Fno and half angle of view ω and variable range.

[table 3]

Fig. 2 to 5 is curve maps of representing the some aberrations in the numerical example 1 respectively.In other words, the some aberrations during Fig. 2 infinite distance of being shown in (focal length=5.15) under the wide-angle side state focuses on.Some aberrations during the infinite distance that Fig. 3 is shown in (focal length=10.01) under the intermediate angle end state focuses on.Some aberrations during the infinite distance that Fig. 4 is shown in (focal length=19.49) under the angle end state of dolly-out,ing dolly-back focuses on.Fig. 5 is shown in the some aberrations during the focusing of the object distance that has 2m under the angle end state of dolly-out,ing dolly-back.

In each of Fig. 5, the longitudinal axis of spherical aberration curve map is represented the ratio with open F number (open F number), and its transverse axis is represented values of defocus at Fig. 2.In addition, solid line is illustrated in the spherical aberration of d line (wavelength is 587.6nm).In addition, replace the spherical aberration that the length dotted line is illustrated in g line (wavelength is 435.8nm).In addition, dotted line is illustrated in the spherical aberration of C line (wavelength is 656.3nm).In each astigmatism curve map, ordinate is represented the visual angle, and horizontal ordinate is represented values of defocus, and solid line is represented radially (sagittal) plane of delineation, and dotted line is represented warp-wise (meridional) plane of delineation.In each distortion curve figure, ordinate is represented the visual angle, and horizontal ordinate representes with % to be the distortion of unit.

As conspicuous from each aberration curve figure, obviously, numerical example 1 illustrates each aberration and excellent imaging performance of advantageously proofreading and correct.

< second embodiment >

Fig. 6 is the synoptic diagram that diagram is arranged according to the lens of the zoom lens 2 of second embodiment of the invention.Zoom lens 2 comprise six lens.

The first lens combination GR1 comprises that wherein two surfaces form aspheric negative lens G1 and positive lens G2.These lens G1 and G2 are with the sequence arrangement from the subject side to the image-side.

The second lens combination GR2 comprises that wherein two surfaces form aspheric positive lens G3, positive lens G4 and negative lens G5.These lens G3, G4 and G5 combine to form cemented lens, simultaneously with the sequence arrangement from the subject side to the image-side.The second lens combination GR2 can move on almost vertical with optical axis direction.Therefore, on almost perpendicular to the direction of optical axis, move second lens combination GR2 permission image shift.

The 3rd lens combination GR3 comprises that wherein two surfaces form aspheric positive lens.

In the subject side of the second lens combination GR2, aperture diaphragm IR (aperture surface s5) is arranged near the second lens combination GR2.During zoom, aperture diaphragm IR moves on optical axis direction, makes up with the second lens combination GR2 simultaneously.

Table 4 is represented the lens data through the numerical example 2 of zoom lens 2 acquisitions that numerical value specifically are applied to second embodiment.

[table 4]

si	ri	di	ni	vi
					1(ASP)	120.0000	0.800	1.85135	40.1
2(ASP)	5.6958	1.650
					3	8.7462	1.470	1.92286	20.9
4	16.8460	Variable
					5 (aperture diaphragms)	INFINITY	-0.200
6(ASP)	6.0415	1.600	1.69350	53.2
					7(ASP)	-17.1356	0.100
8	10.3723	1.600	1.83481	42.7
					9	-5.8161	0.430	1.69895	30.1
10	3.4198	Variable
					11(ASP)	30.6927	1.550	1.52470	56.2
12(ASP)	-12.2195	Variable
					13	INFINITY	0.300	1.51680	64.2
14	INFINITY

In zoom lens 2, the image-side of the positive lens G6 of the subject side of the positive lens G3 of the image-side of the positive lens G3 of the subject side of the positive lens G3 of the image-side of the negative lens G1 of the subject side of the negative lens G1 of first lens combination GR1 surface (s1), first lens combination GR1 surface (s2), second lens combination GR2 surface (s6), second lens combination GR2 surface (s7), the 3rd lens combination GR3 surface (s11) and the 3rd lens combination GR3 surface (s12) forms aspheric surface respectively.Taper COEFFICIENT K and aspheric the 4th, the 6th, the 8th and the tenth asphericity coefficient A4, A6, A8 and A10 in the table 5 expression numerical example 2.

[table 5]

si

K

A4

A6

A8

A10

1

0

-3.66467E-04

2.07015E-05

-4.79770E-07

4.43088E-09

2

0

-7.56934E-04

1.71097E-05

-2.36442E-07

-1.78657E-08

6

0

-1.43565E-03

-1.97423E-05

-1.74215E-05

6.61035E-07

7

0

-2.56836E-04

4.50758E-06

-2.46634E-05

1.73018E-06

11

0

5.78132E-04

-5.93784E-05

2.17382E-06

-3.59561E-08

12

0

1.24265E-03

-9.70586E-05

3.40589E-06

-5.06125E-08

In zoom lens 2; During wide-angle side state and the zoom between the end state of dolly-out,ing dolly-back, surface distance d10 between the surface distance d4 between the first lens combination GR1 and the second lens combination GR2, the second lens combination GR2 and the 3rd lens combination GR3 and the surface distance d12 between the 3rd lens combination GR3 and the low-pass filter LPF change respectively.The F that table 6 is illustrated under wide-angle side state (focal length=4.79), intermediate focus location status (focal length=9.07) and the end state of dolly-out,ing dolly-back (focal length=18.11) in the numerical example 2 counts Fno and half angle of view ω and variable range.

[table 6]

Fig. 7 to 10 is curve maps of representing the some aberrations in the numerical example 2 respectively.Some aberrations during the infinite distance that Fig. 7 is shown in (focal length=4.79) under the wide-angle side state focuses on.Some aberrations during the infinite distance that Fig. 8 is shown in (focal length=9.07) under the intermediate angle end state focuses on.Some aberrations during the infinite distance that Fig. 9 is shown in (focal length=18.11) under the angle end state of dolly-out,ing dolly-back focuses on.In addition, Figure 10 is shown in the some aberrations during the focusing of the object distance that has 2m under the angle end state of dolly-out,ing dolly-back.

In each of Figure 10, the longitudinal axis of spherical aberration curve map is represented the ratio with the open F number, and its transverse axis is represented values of defocus at Fig. 7.In the accompanying drawings, solid line is illustrated in the spherical aberration of d line (wavelength is 587.6nm).In addition, replace the spherical aberration that the length dotted line is illustrated in g line (wavelength is 435.8nm).In addition, dotted line is illustrated in the spherical aberration of C line (wavelength is 656.3nm).In each astigmatism curve map, ordinate is represented the visual angle, and horizontal ordinate is represented values of defocus, and solid line is represented the radially plane of delineation, and dotted line is represented the warp-wise plane of delineation.In each distortion curve figure, ordinate is represented the visual angle, and horizontal ordinate representes with % to be the distortion of unit.

As conspicuous from each aberration curve figure, obviously, numerical example 2 illustrates each aberration and excellent imaging performance of advantageously proofreading and correct.

< the 3rd embodiment >

Figure 11 is the lens arrangement of diagram according to the zoom lens 3 of third embodiment of the invention.Zoom lens 3 comprise six lens.

The second lens combination GR2 comprises that wherein two surfaces form aspheric positive lens G3, positive lens G4 and negative lens G5.These lens G3, G4 and G5 combine to form cemented lens, simultaneously with the sequence arrangement from the subject side to the image-side.The second lens combination GR2 can move on almost vertical with optical axis direction.Therefore, on almost perpendicular to the direction of optical axis, move second lens combination GR2 permission image shift.The 3rd lens combination GR3 comprises that wherein two surfaces form aspheric positive lens G6.

Table 7 is represented the lens data through the numerical example 3 of zoom lens 3 acquisitions that numerical value specifically are applied to the 3rd embodiment.

[table 7]

si	ri	di	ni	vi
					1(ASP)	150.0000	0.800	1.85135	40.1
2(ASP)	5.6871	1.623
					3	8.6931	1.500	1.92286	20.9
4	16.8575	Variable
					5 (aperture diaphragms)	INFINITY	-0.200
6(ASP)	6.1626	1.600	1.69350	53.2
					7(ASP)	-16.2346	0.100
8	10.2632	1.600	1.83481	42.7

9	-5.8000	0.430	1.69895	30.1
					10	3.4362	Variable
11(ASP)	26.6453	1.550	1.52470	56.2
					12(ASP)	-13.0106	Variable
13	INFINITY	0.300	1.51680	64.2
					14	INFINITY

In zoom lens 3, the image-side of the positive lens G6 of the subject side of the positive lens G6 of the image-side of the positive lens G3 of the subject side of the positive lens G3 of the image-side of the negative lens G1 of the subject side of the negative lens G1 of first lens combination GR1 surface (s1), first lens combination GR1 surface (s2), second lens combination GR2 surface (s6), second lens combination GR2 surface (s7), the 3rd lens combination GR3 surface (s11) and the 3rd lens combination GR3 surface (s12) forms aspheric surface respectively.Taper COEFFICIENT K and aspheric the 4th, the 6th, the 8th and the tenth asphericity coefficient A4, A6, A8 and A10 in the table 8 expression numerical example 3.

[table 8]

si

K

A4

A6

A8

A10

1

0

-3.57005E-04

2.02377E-05

-4.77160E-07

4.44181E-09

2

0

-7.53123E-04

1.84378E-05

-3.21116E-07

-1.72326E-08

6

0

-1.49170E-03

-4.43785E-05

-1.41092E-05

3.11886E-07

7

0

-3.34178E-04

-1.64374E-05

-2.21275E-05

1.49390E-06

11

0

8.74658E-04

-5.83310E-05

2.58879E-06

-6.14856E-08

12

0

1.57240E-03

-9.45672E-05

3.58391E-06

-7.34202E-08

In zoom lens 3; During wide-angle side state and the zoom between the end state of dolly-out,ing dolly-back, surface distance d10 between the surface distance d4 between the first lens combination GR1 and the second lens combination GR2, the second lens combination GR2 and the 3rd lens combination GR3 and the surface distance d12 between the 3rd lens combination GR3 and the low-pass filter LPF change respectively.The F that table 9 is illustrated under wide-angle side state (focal length=4.69), intermediate focus location status (focal length=8.78) and the end state of dolly-out,ing dolly-back (focal length=17.72) in the numerical example 3 counts Fno and half angle of view ω and variable range.

[table 9]

Figure 12 to 15 is curve maps of representing the some aberrations in the numerical example 3 respectively.In other words, the some aberrations during Figure 12 infinite distance of being shown in (focal length=4.69) under the wide-angle side state focuses on.Some aberrations during the infinite distance that Figure 13 is shown in (focal length=8.78) under the intermediate angle end state focuses on.Some aberrations during the infinite distance that Figure 14 is shown in (focal length=17.72) under the angle end state of dolly-out,ing dolly-back focuses on.Figure 15 is shown in the some aberrations during the focusing of the object distance that has 2m under the angle end state of dolly-out,ing dolly-back.

In each of Figure 15, the longitudinal axis of spherical aberration curve map is represented the ratio with the open F number, and its transverse axis is represented values of defocus at Figure 12.In addition, solid line is illustrated in the spherical aberration of d line (wavelength is 587.6nm), and alternately the length dotted line is illustrated in the spherical aberration of g line (wavelength is 435.8nm), and dotted line is illustrated in the spherical aberration of C line (wavelength is 656.3nm).In each astigmatism curve map, ordinate is represented the visual angle, and horizontal ordinate is represented values of defocus, and solid line is represented the radially plane of delineation, and dotted line is represented the warp-wise plane of delineation.In each distortion curve figure, ordinate is represented the visual angle, and horizontal ordinate representes with % to be the distortion of unit.

As conspicuous from each aberration curve figure, obviously, numerical example 3 illustrates each aberration and excellent imaging performance of advantageously proofreading and correct.

< the 4th embodiment >

Figure 16 is the lens arrangement of diagram according to the zoom lens 4 of fourth embodiment of the invention.Zoom lens 4 comprise six lens.

The 3rd lens combination GR3 comprises that wherein two surfaces form aspheric positive lens G6.

Table 10 is represented the lens data through the numerical example 4 of zoom lens 4 acquisitions that numerical value specifically are applied to the 4th embodiment.

[table 10]

si	ri	di	ni	vi
					1(ASP)	63.1468	0.800	1.85135	40.1
2(ASP)	6.1603	1.650
					3	8.2440	1.454	2.00272	19.3
4	12.1514	Variable
					5 (aperture diaphragms)	INFINITY	-0.300
6(ASP)	5.9272	1.603	1.61881	63.9
					7(ASP)	-24.8103	0.100
8	6.9641	1.572	1.81600	46.6
					9	-21.9947	0.430	1.69895	30.1
10	3.3847	Variable
					11(ASP)	31.6059	1.550	1.52470	56.2
12(ASP)	-12.5205	Variable
					13	INFINITY	0.300	1.51680	64.2
14	INFINITY

In zoom lens 4, the image-side of the positive lens G6 of the subject side of the positive lens G6 of the image-side of the positive lens G3 of the subject side of the positive lens G3 of the image-side of the negative lens G1 of the subject side of the negative lens G1 of first lens combination GR1 surface (s1), first lens combination GR1 surface (s2), second lens combination GR2 surface (s6), second lens combination GR2 surface (s7), the 3rd lens combination GR3 surface (s11) and the 3rd lens combination GR3 surface (s12) forms aspheric surface respectively.Taper COEFFICIENT K and aspheric the 4th, the 6th, the 8th and the tenth asphericity coefficient A4, A6, A8 and A10 in the table 11 expression numerical example 3.

[table 11]

si

K

A4

A6

A8

A10

1

0

-4.37782E-04

2.36282E-05

-4.31913E-07

2.90291E-09

2

0

-6.13937E-04

1.22296E-05

6.69552E-07

-2.44767E-08

6

0

-6.84006E-04

1.52610E-07

-5.71428E-06

3.60069E-07

7

0

5.43864E-05

3.47835E-05

-1.09172E-05

7.91728E-07

11

0

6.04682E-04

-9.11019E-05

7.19654E-06

-1.77064E-07

12

0

1.28794E-03

-1.47585E-04

1.00245E-05

-2.32364E-07

In zoom lens 4; During wide-angle side state and the zoom between the end state of dolly-out,ing dolly-back, surface distance d10 between the surface distance d4 between the first lens combination GR1 and the second lens combination GR2, the second lens combination GR2 and the 3rd lens combination GR3 and the surface distance d12 between the 3rd lens combination GR3 and the low-pass filter LPF change respectively.The F that table 12 is illustrated under wide-angle side state (focal length=4.84), intermediate focus location status (focal length=10.15) and the end state of dolly-out,ing dolly-back (focal length=22.91) in the numerical example 4 counts Fno and half angle of view ω and variable range.

[table 12]

Figure 17 to 20 is curve maps of representing the some aberrations in the numerical example 4 respectively.Some aberrations during the infinite distance that Figure 17 is shown in (focal length=4.84) under the wide-angle side state focuses on.Some aberrations during the infinite distance that Figure 18 is shown in (focal length=10.15) under the intermediate angle end state focuses on.Some aberrations during the infinite distance that Figure 19 is shown in (focal length=22.91) under the angle end state of dolly-out,ing dolly-back focuses on.Figure 20 is shown in the some aberrations during the focusing of the object distance that has 2m under the angle end state of dolly-out,ing dolly-back.

In each of Figure 20, the longitudinal axis of spherical aberration curve map is represented the ratio with the open F number, and its transverse axis is represented values of defocus at Figure 17.In the accompanying drawings, solid line is illustrated in the spherical aberration of d line (wavelength is 587.6nm).In addition, replace the spherical aberration that the length dotted line is illustrated in g line (wavelength is 435.8nm).In addition, dotted line is illustrated in the spherical aberration of C line (wavelength is 656.3nm).In each astigmatism curve map, ordinate is represented the visual angle, and horizontal ordinate is represented values of defocus, and solid line is represented the radially plane of delineation, and dotted line is represented the warp-wise plane of delineation.In each distortion curve figure, ordinate is represented the visual angle, and horizontal ordinate representes with % to be the distortion of unit.

As conspicuous from each aberration curve figure, obviously, numerical example 4 illustrates each aberration and excellent imaging performance of advantageously proofreading and correct.

< the 5th embodiment >

Figure 21 is the lens arrangement of diagram according to the zoom lens 5 of fifth embodiment of the invention.Zoom lens 5 comprise six lens.

The second lens combination GR2 comprises: the cemented lens that is provided as the combination of aspheric positive lens G3 and negative lens G4 as one of them surface; Be provided as aspheric positive lens G5 with one of them surface.These lens G3, G4 and G5 are with the sequence arrangement from the subject side to the image-side.The second lens combination GR2 can move on almost vertical with optical axis direction.Therefore, on almost perpendicular to the direction of optical axis, move second lens combination GR2 permission image shift.

Table 13 is represented the lens data through the numerical example 5 of zoom lens 5 acquisitions that numerical value specifically are applied to the 5th embodiment.

[table 13]

si	ri	di	ni	vi
					1(ASP)	60.6971	0.900	1.80139	45.5
2(ASP)	5.8172	1.800
					3	8.1338	1.307	2.00272	19.3
4	11.3466	Variable
					5 (aperture diaphragms)	INFINITY	-0.400
6(ASP)	4.3964	1.989	1.85135	40.1
					7	-11.2657	0.430	1.76182	26.6
8	3.7371	0.301
					9(ASP)	8.4037	1.040	1.74330	49.3

10	62.7439	Variable
			11(ASP)	22.6066	1.600	1.52470	56.2
12(ASP)	-21.0726	Variable
			13	INFINITY	0.300	1.51680	64.2
14	INFINITY

In zoom lens 5, the image-side of the positive lens G6 of the subject side of the positive lens G6 of the image-side of the positive lens G5 of the subject side of the positive lens G3 of the image-side of the negative lens G1 of the subject side of the negative lens G1 of first lens combination GR1 surface (s1), first lens combination GR1 surface (s2), second lens combination GR2 surface (s6), second lens combination GR2 surface (s7), the 3rd lens combination GR3 surface (s11), the 3rd lens combination GR3 surface (s12) forms aspheric surface respectively.Taper COEFFICIENT K and aspheric the 4th, the 6th, the 8th and the tenth asphericity coefficient A4, A6, A8 and A10 in the table 14 expression numerical example 5.

[table 14]

s?i

K

A4

A6

A8

A10

1

0

-4.82525E-04

2.04660E-05

-3.35864E-07

2.05703E-09

2

0

-4.67416E-04

1.69876E-05

4.26620E-07

-1.06193E-08

6

-0.5

4.90886E-04

4.62338E-05

-5.23914E-06

8.21860E-07

9

-0.5

-1.19080E-03

-2.50295E-04

4.69010E-05

-1.20760E-05

11

0

3.53004E-04

-3.97204E-05

1.96026E-06

-3.77835E-08

12

0

8.11090E-04

-7.32262E-05

3.27159E-06

-5.91468E-08

In zoom lens 5; During wide-angle side state and the zoom between the end state of dolly-out,ing dolly-back, surface distance d10 between the surface distance d4 between the first lens combination GR1 and the second lens combination GR2, the second lens combination GR2 and the 3rd lens combination GR3 and the surface distance d12 between the 3rd lens combination GR3 and the low-pass filter LPF change respectively.The F that table 15 is illustrated under wide-angle side state (focal length=4.84), intermediate focus location status (focal length=9.84) and the end state of dolly-out,ing dolly-back (focal length=20.59) in the numerical example 5 counts Fno and half angle of view ω and variable range.

[table 15]

Figure 22 to 25 is curve maps of representing the some aberrations in the numerical example 5 respectively.In other words, the some aberrations during Figure 22 infinite distance of being shown in (focal length=4.84) under the wide-angle side state focuses on.Some aberrations during the infinite distance that Figure 23 is shown in (focal length=9.84) under the intermediate angle end state focuses on.Some aberrations during the infinite distance that Figure 24 is shown in (focal length=20.59) under the angle end state of dolly-out,ing dolly-back focuses on.Figure 25 is shown in the some aberrations during the focusing of the object distance that has 2m under the angle end state of dolly-out,ing dolly-back.

In each of Figure 25, the longitudinal axis of spherical aberration curve map is represented the ratio with the open F number, and its transverse axis is represented values of defocus at Figure 22.In the accompanying drawings, solid line is illustrated in the spherical aberration of d line (wavelength is 587.6nm).In addition, replace the spherical aberration that the length dotted line is illustrated in g line (wavelength is 435.8nm).In addition, dotted line is illustrated in the spherical aberration of C line (wavelength is 656.3nm).In each astigmatism curve map, ordinate is represented the visual angle, and horizontal ordinate is represented values of defocus, and solid line is represented the radially plane of delineation, and dotted line is represented the warp-wise plane of delineation.In each distortion curve figure, ordinate is represented the visual angle, and horizontal ordinate representes with % to be the distortion of unit.

As conspicuous from each aberration curve figure, obviously, numerical example 5 illustrates each aberration and excellent imaging performance of advantageously proofreading and correct.

[summary of conditional expression]

Table 16 illustrates each value that arrives use in (4) respectively about the above-mentioned conditional expression (1) of

zoom lens

1,2,3,4 and 5.

In other words, Da, Db, Ya, Yb, ZAa1-ZRa1, ZAa2-ZRa2, Ca1, Ca2, N, f1, ZAb1-ZRb1, ZAb1-ZRb2, Cb1, Cb2, Nb, f3, ASPa1, ASPa2, ASPb1 and the ASPb2 in the table 16 expression conditional expression (1) to (4).

[table 16]

As tangible from table 16,

zoom lens

1,2,3,4 and 5 are configured to satisfy respectively above-mentioned conditional expression (1) to (4).

[configuration of image pick-up device]

Next, with the configuration of describing according to the image pick-up device of the embodiment of the invention.

The image pick-up device of present embodiment comprises zoom lens and will convert the imaging device of electric signal through the optical imagery that zoom lens form into.

In image pick-up device, zoom lens comprise from the subject side to the image-side by first lens combination with negative refractive power of following sequence arrangement, the 3rd lens combination that has second lens combination of positive refractive power and have positive refractive power.

In the image pick-up device of present embodiment; When the positioning lens state is changed into when dolly-out,ing dolly-back the end state from the wide-angle side state; Second lens combination moves towards object on optical axis direction, and first lens combination and the 3rd lens combination move on the optical axis direction with reduce the interval between first lens combination and second lens combination and increase by second lens combination and the 3rd lens combination between the interval.

In addition, in the image pick-up device of present embodiment, when changing object's position, zoom lens are carried out short distance and are focused on through on optical axis direction, moving the 3rd lens combination.

In addition, in the image pick-up device of present embodiment, zoom lens comprise first lens combination, and it comprises from the image-side to the subject side negative lens and positive lens by this sequence arrangement.The 3rd lens combination comprises positive lens.Two surfaces of the negative lens of first lens combination are respectively aspheric surfaces.Two surfaces of the positive lens of the 3rd lens combination are respectively aspheric surfaces.

In aforesaid image pick-up device of the present invention, first lens combination of zoom lens comprises negative lens and the positive lens that two surfaces of each lens wherein are aspheric surfaces.The 3rd lens combination comprises wherein its two positive lenss that the surface is an aspheric surface.

Therefore, the quantity of the lens in each lens combination is made as enough advantageously lens of the minimum number of correcting spherical aberration, astigmatism, aberration etc.Under the situation that thickness reduces, under the situation that particularly thickness of telescopic lens type image pick-up device reduces, can when holding optical system, carry out.

The zoom lens of structure present embodiment make its expression formula that meets the following conditions:

(1)0.10＜ASPa1＜0.36；

(2)-0.05＜ASPa2＜-0.02；

(3) 0＜ASPb1＜0.20; And

(4) 0.04＜ASPb2＜0.15, wherein

ASPa1＝(ZAa1-ZRa1)/{Ca1·(Na-1)·f1}，

ASPa2＝(ZAa2-ZRa2)/{Ca2·(1-Na)·f1}，

ASPb1＝(ZAb1-ZRb1)/{Cb1·(Nb-1)·f3}，

ASPb2＝(ZAb2-ZRb2)/{Cb2·(1-Nb)·f3}，

Ya＝4Da，

Yb＝2Db，

F1: the focal length of said first lens combination,

F3: the focal length of said the 3rd lens combination.

The expression formula if image pick-up device satisfies condition (1) then can reasonably represent aspheric effect, and the aberration compensation that can carry out is to improve the optical property of zoom lens.

In addition, the expression formula if image pick-up device satisfies condition (2) then can reasonably represent aspheric effect, and the aberration compensation that can carry out.As a result, can realize that the improvement of optical property and the simplification of the negative lens in first lens combination form.

In addition, the expression formula if image pick-up device satisfies condition (3) then can reasonably represent aspheric effect, and the aberration compensation that can carry out is to improve the optical property of zoom lens.

In addition, the expression formula if image pick-up device satisfies condition (4) then can reasonably represent aspheric effect, and the aberration compensation that can carry out is to improve the optical property of zoom lens.

Figure 26 illustrates the block diagram of the configuration of digital camera according to an embodiment of the invention.

Image pick-up device (digital camera) 100 comprises the camera block 10 with image capturing functionality.Image pick-up device 100 also comprises signal processing 20 and the record of carries out image signal and the image processing section 30 of reproduction processes of carrying out signal Processing (as analog to digital conversion of the picture signal of catching).In addition, image pick-up device 100 comprise the LCD (LCD) 40 of the image etc. of display capture, from storage card 1000 reads image data or CPU (CPU) 60 that view data is write the reader/writer (R/W) 50 of storage card 1000 and controls whole device.Image pick-up device 100 also comprises: be used for the importation 70 of user's input operation, it is by structures such as various switches; And the lens drive control part 80 of the driving of the lens that provide in the control camera block 10.

Camera block 10 for example comprises such optical system, and it comprises the zoom lens 11 (can use the

zoom lens

1,2 of any embodiment of the present invention and each of 3) of using any embodiment of the present invention and like the imaging device 12 of charge-coupled device (CCD) or complementary metal oxide semiconductor (CMOS) (CMOS).

Various signal Processing are carried out in camera signal processing section 20, comprising: will be the correction of digital signal, denoising, picture quality from the output conversion of signals of imaging equipment 12 and be luminance signal and colour difference signal with conversion of signals.

Image processing section 30 is carried out compression and encoding process and decompress(ion) and decoding processing based on the predetermined image data layout to picture signal; And like the conversion of the data requirement of resolution.

LCD 40 has the function that shows various data (like the mode of operation of user to importation 70).

R/W 50 will be write on the storage card 1000 and read recorded image data on the storage card 1000 by image processing section 30 image encoded data.

CPU 60 is used as the control and treatment part of each circuit block of installing on the control image pick-up device 100, and based on each circuit blocks of control such as command input signals from importation 70.

Importation 70 for example comprises shutter release button that is used for shutter operation and the mode selection switch that is used for select operating mode.Importation 70 will output to CPU 60 corresponding to the command input signals of user's operation.

Lens drive control part 80 is based on the control signal from CPU 60, and control is used for driving the motor (not shown) of the lens that zoom lens 11 provide etc.

Storage card 1000 for example is the semiconductor memory that is attached to the slot that is connected to R/W 50 removedly.

[operation of image pick-up device]

Below, with the operation of describing image pick-up device 100.

Under the holding state of taking, under the control of CPU 60, the picture signal of catching with block of lense 10 outputs to camera signal processing section 20, outputs to LCD 40 then, thereby is shown as through (camera-through) image of camera.When 70 inputs were used for the command input signals of zoom from the importation, CPU 60 outputed to lens drive control part 80 with control signal, and moves the predetermined lens in the zoom lens 11 based on the control of lens drive control part 80.

When discharging the shutter (not shown) that provides in the block of lense 10 according to the command input signals from importation 70, the picture signal of catching outputs to image processing section 30 from camera signal processing section 20.Then, compression of picture signal experience and encoding process.Subsequently, conversion of signals is the numerical data with predetermined format.Data converted outputs to reader/writer 50, and writes storage card 1000.

For example, when half by or when being used to write down by the shutter release button of importation 70 entirely, can carry out focusing, therefore, lens drive control part 80 allows predetermined lens in the zoom lens 11 based on moving from the control signal of CPU 60.

In order to reproduce image stored data in the storage card 1000; Operation according to importation 70; Reader/writer 50 reads the desired images data from storage card 1000, decompress(ion) and decoding processing that image processing section 30 is carried out view data, and device for playing back image signals outputs to LCD 40 then.Therefore, display reproduction image.

In the above-described embodiments, although be applied to digital camera according to the image pick-up device of the embodiment of the invention, image pick-up device can be not limited to digital camera.Image pick-up device according to any embodiment can be widely applied to cell phone, and digital camera and camera part like the digital input/output device of PDA(Personal Digital Assistant) wherein are provided.

The application comprises and is involved on the February 18th, 2009 of disclosed theme in the japanese priority patent application JP 2009-035830 that Jap.P. office submits to, incorporates its full content by reference at this.

It will be appreciated by those skilled in the art that depending on design requirement various modifications, combination, son combination and change can occur with other factors, as long as they are in the scope of claim or its equivalent.

Claims

1. zoom lens comprise:

First lens combination with negative refractive power;

Second lens combination with positive refractive power; And

The 3rd lens combination with positive refractive power, said three lens combination are arranged from the subject side to the image-side in order, wherein

When the positioning lens state changes to when dolly-out,ing dolly-back the end state from the wide-angle side state; Said second lens combination moves towards object on optical axis direction, and said first lens combination and said the 3rd lens combination move on the said optical axis direction with reduce the interval between said first lens combination and said second lens combination and increase said second lens combination and said the 3rd lens combination between the interval;

When changing object's position, focus on through the mobile execution short distance of said the 3rd lens combination on optical axis direction;

Said first lens combination comprises negative lens and the positive lens with the sequence arrangement from the subject side to the image-side;

Said the 3rd lens combination comprises positive lens;

Two surfaces of the said negative lens of said first lens combination are respectively aspheric surfaces;

Two surfaces of the said positive lens of said the 3rd lens combination are respectively aspheric surfaces; And

Satisfy following conditions expression formula (1) and arrive (4):

(1)0.10＜ASPa1＜0.36；

(2)-0.05＜ASPa2＜-0.02；

(3) 0＜ASPb1＜0.20; And

(4) 0.04＜ASPb2＜0.15, wherein

ASPa1＝(ZAa1-ZRa1)/{Ca1·(Na-1)·f1}，

ASPa2＝(ZAa2-ZRa2)/{Ca2·(1-Na)·f1}，

ASPb1＝(ZAb1-ZRb1)/{Cb1·(Nb-1)·f3}，

ASPb2＝(ZAb2-ZRb2)/{Cb2·(1-Nb)·f3}，

Da is defined as the thickness of the said negative lens on the said optical axis of said first lens combination,

Db is defined as the thickness of the said positive lens on the said optical axis of said first lens combination,

Ya＝4Da，

Yb＝2Db，

ZRa1 be defined as the paraxial curvature surface of subject side of the said negative lens from said first lens combination optical axis, be in the coordinate on the optical axis direction at height corresponding to Ya,

ZRa2 be defined as the paraxial curvature surface of image-side of the said negative lens from said first lens combination optical axis, be in the coordinate on the optical axis direction at height corresponding to Ya;

ZAa1 be defined as the said negative lens from said first lens combination the aspheric optical axis of subject side, be in the coordinate on the optical axis direction at height corresponding to Ya;

ZAa2 be defined as the said negative lens from said first lens combination the aspheric optical axis of image-side, be in the coordinate on the optical axis direction at height corresponding to Ya;

Ca1 is defined as the aspheric paraxial curvature of subject side of the said negative lens in said first lens combination,

Ca2 is defined as the aspheric paraxial curvature of image-side of the said negative lens in said first lens combination,

Na is defined as the refractive index of the e line of the said negative lens in said first lens combination,

F1 is defined as the focal length of said first lens combination,

ZRb1 be defined as the paraxial curvature surface of subject side of the said positive lens from said first lens combination optical axis, be in the coordinate on the optical axis direction at height corresponding to Yb,

ZRb2 be defined as the paraxial curvature surface of image-side of the said positive lens from said first lens combination optical axis, be in the coordinate on the optical axis direction at height corresponding to Yb;

ZAb1 be defined as the said positive lens from said first lens combination the aspheric optical axis of subject side, be in the coordinate on the optical axis direction at height corresponding to Yb;

ZAb2 be defined as the said positive lens from said first lens combination the aspheric optical axis of image-side, be in the coordinate on the optical axis direction at height corresponding to Yb;

Cb1 is defined as the aspheric paraxial curvature of subject side of the said positive lens in said first lens combination,

Cb2 is defined as the aspheric paraxial curvature of image-side of the said positive lens in said first lens combination,

Nb is defined as the refractive index of the e line of the said positive lens in said first lens combination, and

F3 is defined as the focal length of said the 3rd lens combination.

2. zoom lens as claimed in claim 1, wherein

Said second lens combination comprises two positive lenss and a negative lens.

3. zoom lens as claimed in claim 1, wherein

At least one surface of lens in said second lens combination has aspheric surface.

4. zoom lens as claimed in claim 2, wherein

At least one surface of said lens in said second lens combination has aspheric surface.

5. zoom lens as claimed in claim 1, wherein

Said second lens combination can squint with migrated image on the direction vertical with optical axis basically.

6. zoom lens as claimed in claim 2, wherein

7. zoom lens as claimed in claim 3, wherein

8. zoom lens as claimed in claim 4, wherein

9. image pick-up device comprises zoom lens and will be converted into the imaging device of electric signal by the optical imagery that said zoom lens form, wherein

Said zoom lens comprise: have first lens combination of negative refractive power, the 3rd lens combination that has second lens combination of positive refractive power and have positive refractive power, said three lens combination are arranged from the subject side to the image-side in order, wherein

Said the 3rd lens combination comprises positive lens;

Two surfaces of the said positive lens of said the 3rd lens combination are respectively aspheric surfaces; And satisfy following conditions expression formula (1) and arrive (4):

(1)0.10＜ASPa1＜0.36；

(2)-0.05＜ASPa2＜-0.02；

(3) 0＜ASPb1＜0.20; And

(4) 0.04＜ASPb2＜0.15, wherein

ASPa1＝(ZAa1-ZRa1)/{Cal·(Na-1)·f1}，

ASPa2＝(ZAa2-ZRa2)/{Ca2·(1-Na)·f1}，

ASPb1＝(ZAb1-ZRb1)/{Cb1·(Nb-1)·f3}，

ASPb2＝(ZAb2-ZRb2)/{Cb2·(1-Nb)·f3}，

Ya＝4Da，

Yb＝2Db，

F1 is defined as the focal length of said first lens combination,

F3 is defined as the focal length of said the 3rd lens combination.